This PhD project within SYNFERON research project focuses on exploiting the potential for syngas fermentation to gaseous and liquid biofuels, such as methane and alcohols, by mixed microbial consortia, MMC, as opposed to biological conversions carried out by single microbial strains or well-defined microbial co-cultures.
Mixed microbial consortia of anaerobic bacteria and methanogenic archaea can convert CO, CO2 and H2 into CH4.
These microbial consortia are massively available in environments like waste/wastewater treatment processes; they come, therefore, at no cost.
The main biochemical reactions may take place simultaneously leading to a final efficiency of 0.25 mol of CH4 per mol of CO plus 0.25 mol of CH4 per mol of H2.
Depending on the syngas composition this may result to an impressive 0.4 m3 STP CH4 per kg of organic solids gasified.
Research on production of alcohols and chemicals (mainly acids) from syngas has been mainly focused so far on the use of well-defined, wild or genetically modified microbial cultures or co-cultures.
Mixed microbial consortia fermentations (MMC) is a recently emerging field with very high potential, which have the advantage of being carried out by stable mixed microbial consortia, as typically found in nature and therefore not requiring sterile conditions.
MMC have been successfully applied so far for the production of bioplastics and are currently being under investigation worldwide as the fermentation technology of the future for the production of bulk chemicals from a number of feedstocks.
The big asset of MMC is the lower operation cost, which combined with cost-efficient downstream processing, can really make a difference to the economy of an industrial process.
The objectives of the PhD project are:
- Enriching highly efficient mixed microbial consortia for fermenting syngas to methane and alcohols
- Applying thermodynamics to finding out favorable enrichment conditions for specific biotransformations
- Explaining and predicting the dominant metabolic routes under batch and continuous operation based on the interplay of thermodynamics and microbial growth kinetics
- Kinetically characterizing the microbial consortia converting syngas to methane and modeling the overall process
Proposing a process scheme and operating conditions under which conversion of syngas to alcohols can occur by mixed microbial consortia
Main supervisor: Hariklia Gavala
Co- supervisor: Ioannis Skiadas